Author

Year of Publication

2014

College

Public Health

Degree Name

Master of Public Health (M.P.H.)

Committee Chair

Pamela Teaster

Committee Member

Richard Crosby

Committee Member

Robin Vanderpool, DrPH, CHES

Abstract

Despite the existence of safe and effective vaccines, measles and rubella present a major public health problem in many developing countries, disproportionally affecting low-income populations.1-3 Indeed, measles and rubella remain two of the leading causes of death and congenital defects in children worldwide.4-6 In 2008, an estimated 10 million new cases and 164,000 deaths were reported from measles alone.3 During the same time period, the United Nations International Children's Emergency Fund (UNICEF) reported an estimated 110,000 cases of Congenital Rubella Syndrome (CRS) in developing countries, with the continent of Africa shouldering 38% of the disease burden.7 Measles is a highly infectious viral disease caused by the measles virus. The infection is transmitted person-to-person by contact with contaminated droplets in the air. 6,8,9 The symptoms of the diseases are characterized by conjunctivitis, coryza, malaise, and a generalized maculopapular rash.6,8,9 The diseases has a case fatality rate of 10%, which is largely due to an increased susceptibility of measles-infected persons contracting secondary bacterial infections.1,3,9, Similar to the transmission and symptoms of measles, rubella is by comparison less severe. Caused by the rubella virus, the rubella diseases usually presents as a mild, febrile rash illness in children and adults.4 Importantly, when a woman is infected with rubella early in her pregnancy, particularly during the first 16 weeks, the virus can result in miscarriage, fetal death, or an infant born with CRS.4 In 1999, a reported 61% of global deaths from measles occurred in Sub-Saharan Africa.10 This high percentage prompted many countries in the region to launch accelerated measles control programs to meet the 2005 global target of halving the Dibaya 5 number of measles-related deaths.10 As a result, impressive gains in achieving 75% of the global reduction in measles deaths occurred in Africa.10 The great strides made in reducing measles-related deaths were achieved by institutionalizing routine immunization programs through the World Health Organization’s Expanded Program on Immunization (EPI), which is a disease prevention activity aimed at reducing morbidity and mortality from childhood diseases preventable by immunization.10-12 WHO member countries administer EPI services as part of their routine immunization schedule against childhood killer diseases such as Tuberculosis, Polio, Whooping cough, measles and Tetanus. Vaccines against these target diseases are known as the eight EPI vaccines which includes: one dose of Bacillus Calmette-Guerin (BCG), three doses of DPT (against diphtheria, pertussis, and tetanus), three doses of oral polio vaccine, and one dose of measles vaccine.11,13,14 WHO recommends that these eight vaccines be given routinely to all children from birth through 12 months.13,14 A safe and effective rubella-containing vaccine (RCVs) has been available since the 1960s.4,15 In developed nations, RCVs were promptly introduced in national immunization schedules, however, until the 1990s, the vaccine was not available in developing nations due to (1) the cost of the new vaccine and (2) insufficient documentation of the burden caused by rubella virus in these parts of the world.4 Rubella and RCS were vastly underreported in developing countries because of the difficulties associated with surveillance.4 A cost-benefit analysis of introducing RCV in national immunization schedules has shown such an intervention to be cost-effective, contrary to past concerns.4,16 According to S.E. Reef et al, studies conducted in Barbados and Guyana revealed that the Dibaya 6 lifetime cost of treating a single CRS case was estimated to be $50,000 in Barbados and $64,000 in Guyana.4 On the other hand, the rubella vaccine is highly affordable; the same report by S.E. Reef et al shows that the incremental costs of incorporating RCV in measles-rubella (MR) and measles-mumps-rubella (MMR) vaccines using a 10-dose vial are $0.31 and $0.70–$1.37 per dose, respectively.4 In the past, documenting the extent of rubella and CRS were particularly challenging because of the difficulties of diagnosis and reporting in settings with limited medical resources.4,16 However, through progress made in medical technology, there has been great improvement in disease surveillance systems.4 This has prompted an increase in the case reporting of rubella to WHO by member states. For example, from 2000-2009, the reported rubella cases in the African region increased from 865 to 17,388, and number of reporting countries increased from 7 to 38.4 In recent decades, the progress made in better identifying cases prompted many member states to introduce RCV in national immunization schedules. Therefore, as of 2009, 130 of 193 member states had introduced RCV, including two countries from the WHO African region.4,16 The low introduction rate of RCVs in Africa is due to the lack of establishing rubella elimination, control, or prevention goals in the region.15,16 From 2000-2009, this hampered African countries from addressing the 20-fold increase in rubella cases.4,15 Through EPI, most African countries already administer measles-containing vaccine (MCV) as part of their national routine immunization program.11 Thus, switching from a single measles antigen to a combined MR or MMR vaccine is not only cost effective, but presents an opportunity to address the rising rates of rubella and CRS.15 Recently, the feasibility of switching from MCV to MR has been made possible through Dibaya 7 funding from the Global Alliance for Vaccines and Immunization. For funding consideration, GAVI-eligible countries – the majority of which are found in sub-Saharan Africa – must meet one of two requirements: (1) maintain high immunization coverage of the eight EPI vaccines, and (2) achieve and sustain a >80% coverage of MCV. 17 In an attempt to meet the requirement set by GAVI, 16 African countries have sustained MCV coverage of >80% (i.e., Algeria, Botswana, Burundi, Cape Verde, Eritrea, Gambia, Ghana, Lesotho, Malawi, Rwanda, Sao Tome, Sudan, Swaziland, Togo, Tanzania, and Zambia),4 of which only Rwanda has introduced RCV into its immunization schedule as of 2013.18